Re: Help-octave Digest, Vol 45, Issue 10

[Bart Vandewoestyne]

On Mon, Dec 07, 2009 at 09:02:51AM -0600, address@hidden wrote:
>
> The style of supplying Jacobian is not supported in the 3.2 version of
> fsolve. Instead, one should use the Matlab-compatible style:
> 
>  function [y,J] = f_3d(x)
> 
>  y(1) = 16*x(1)^4 + 16*x(2)^4 + x(3)^4 - 16;
>  y(2) =    x(1)^2 +    x(2)^2 + x(3)^2 - 3;
>  y(3) =    x(1)^3 -    x(2);
> 
> if (nargout > 1)
>  J = zeros(3,3);
>  J = [64*x(1)^3 64*x(2)^3 4*x(3)^3; ...
>        2*x(1)    2*x(2)   2*x(3);   ...
>        3*x(1)^2   -1      0];
> endif
> 
> 
> I think this style is preferable not only because of
> Matlab-compatibility, but also because y and J are usually closely
> related. It wouldn't be hard to support also the old version, but the
> fact is that it is not there, because nobody asked for it.

OK.  Thanks.  In the meanwhile, i also found that this was the
solution to my problem.

> Apparently the manual wasn't updated. But it has the docstring
> included; so you should pay attention to that.

I'm afraid I don't understande what you mean here.  Can you
explain a bit?

Kind regards,
Bart

-- 
        "Share what you know.  Learn what you don't."